ML14192A677
| ML14192A677 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 08/19/1985 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Utley E CAROLINA POWER & LIGHT CO. |
| Shared Package | |
| ML14192A678 | List: |
| References | |
| TAC-49223, NUDOCS 8508300165 | |
| Download: ML14192A677 (3) | |
Text
August 19, 1985 DISTRIBUION DockeFi eRIC INRC PDR Docket No. 50-261 L PDR Gray File ORB#1 Rdg GRequa TChandrasekaran OELD HThompson EJordan Mr. E. E. Utley, Senior Executive Vice President BGrimes CParrish Power Supply and Engineering & Construction JPartlow ACRS 10 Carolina Power and Light Company Post Office Box 1551 Raleigh, North Carolina 27602
Dear Mr. Utley:
SUBJECT:
SAFETY EVALUATION RELATING TO THE EFFECTS OF TORNADOES ON THE AVAILABILITY OF AUXILIARY FEEDWATER AND SERVICE WATER SYSTEMS FOR H. B. ROBINSON UNIT NO. 2 (TAC NO. 49223)
We have completed our review relating to the effects of tornadoes on the availability of auxiliary feedwater (AFWs) and Service Water Systems (SWS).
By letter dated March 14, 1985 we requested your response to our subject concerns. By letter dated June 13, 1985 you responded to these concerns by providing an addition to the previous tornado missile probabilistic risk assessment. We cohclude that this additional analysis has demonstrated the acceptability of the AFWS at H. B. Robinson Unit 2 as it relates to protection against the affects of tornado missiles.
We have also addressed the protection of the SWS in connection with its ultimate heat sink function. As stated in the enclosed SER, the concern regarding potential damage to the SWS pump motors (the only exposed SWS components of concern) from tornado missiles is of secondary importance in comparison with potential damage to them as a result of the direct effect of the tornado (wind load) itself.
It is our judgment that providing additional protection to the SWS pump motors against the direct effect of torna go winds is not cost beneficial given the damage probability of about 10- per year and recognizing the uncertainty and conservatism inherent in the estimate. As stated in the SER, we believe there is reasonable assurance that tornadoes in the area of the pump motors will not cause the loss of the essential cooling function for the plant provided by the SWS and, therefore, the requirements of General Design Criteria 2 and 4 are satisfied.
93508300165 850819 PDR.
ADOCK 05000261 PDR
Mr. E. August 19, 1985 This completes our effort regarding the effects of tornadoes on the AFWS and SWS under TAC 49223. We have enclosed a copy of our Safety Evaluation for your information.
Sincerely,
/s/SVarga Steven A. Varga, Chief Operating Reactors Branch #1 Division of Licensing
Enclosure:
As stated cc w/enclosure:
See next page ORB#1:DL ORB#1:
B -0 #1:DL CParrish GReq#
8/j/85 8/,
8Y'8
Mr. E. E. Utley Carolina Power & Light Company H. B. Robinson 2 cc:
G. F. Trowbridge, Esquire Mr. Dayne H. Brown, Chief Shaw, Pittman, Potts and Trowbridge Radiation Protection branch 1800 M Street', N.W.
Division of Facility Services Washington, DC 20036 Department of Human Resources P.O. Box 12200 Raliegh, North Carolina 27605 Mr. McCuen Morrell, Chairman Darlington County Board of Supervisors County Courthouse Darlington, South Carolina 29535 State Clearinghouse Division of Policy Development 116 West Jones Street Raleigh, North Carolina 27603, Attorney General Department of Justice
-Justice Building Raleigh, North Carolina 27602 U.S. Nuclear Regulatory Commission Resident Inspector's Office H. B. Robinson Steam Electric Plant Route 5, Box 413 Hartsville, South Carolina 29550 aRegional Administrator, Region II U.S. Nuclear Regulatory Commission Suite 2900
-11 Marietta Street Atlanta, Georgia 30303 Mr. R. Morgan f-General Manager H. B. Robinson Steam Electric Plant Post Office Box 790 Hartsville, South Carolina 29550